Anecdotally, but having done 100% WFH for over a year now, I think the first point depends a lot on company culture. We're given explicit permission to use work hours to play games/hang out together, specifically because of the lack of traditional social structures. In the same vein, we're given regular time to work on work-related projects of our choosing.

It definitely doesn't work for some people, but a lot of problems I've seen people bring up can be rectified by the employer. Some of them can't be, but those that can shouldn't be expressed as fact.